基于BRDF模型的FY_3D MERSI-Ⅱ场地定标与验证  

Calibration and Validation of FY_3D MERSI-II Based on BRDF model

作　　者：衡岩冰 潘军[1] 高海亮 王凯司 豆新格 Heng Yanbing;Pan Jun;Gao Hailiang;Wang Kaisi;Dou Xinge(College of Geoexploration Science and Technology,Jilin University,Changchun 130012,Jilin,China;The Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100094,China)

机构地区：[1]吉林大学地球探测科学与技术学院,吉林长春130012 [2]中国科学院空天信息创新研究院,北京100094

出　　处：《激光与光电子学进展》2023年第22期339-347,共9页Laser & Optoelectronics Progress

基　　金：国家民用空间基础设施陆地观测卫星共性应用支撑平台(CASPLOS-CCSI);黑土地保护与利用科技创新工程专项资助(XDA28050401)。

摘　　要：FY_3D卫星中分辨率成像仪(MERSI-Ⅱ型)自发射以来,主要应用在气象观测、环境监测、防灾减灾等方面。FY_3D卫星过境时的观测角度会影响定标精度,基于此,提出一种基于双向反射分布函数(BRDF)模型的场地定标方法。2022年7月在敦煌校正场开展星地同步测量实验,并利用2020年7组不同时刻的无人机多角度观测数据基于6种核函数组合方式建立42种BRDF模型。针对不同观测角度下的FY_3D影像,对构建的BRDF模型进行适用性分析。并计算基于BRDF模型传感器各波段的表观反射率与卫星实测的表观反射率相对偏差。结果显示:敦煌场地BRDF模型校正地表反射率时会受卫星观测角度影响,不同模型校正地表反射率之间的差异,受时间及太阳角度的影响不超过1%,受不同核函数组合方式的影响不超过3%。FY_3D MERSI-Ⅱ型2021年B1~B12波段模型计算的与卫星观测的表观反射率平均相对偏差均小于5.22%,2022年B1、B2波段模型计算的与卫星观测的表观反射率平均相对偏差超过8%,其余波段均小于5.74%。The FY_3D satellite medium-resolution imager(MERSI-II)has been primarily used for meteorological observation,environmental monitoring,disaster prevention,and mitigation.As the observation angle of FY_3D satellite transit is expected to affect the calibration accuracy,this study proposes a site calibration method based on bidirectional reflectance distribution function(BRDF)model.In July 2022,a satellite-ground synchronous measurement experiment was conducted in the Dunhuang calibration field,and 42 BRDF models were established based on six kernel-function combinations which included seven sets of unmanned aerial vehicle multiangle observation data at different moments in 2020.Consequently,the applicability of the constructed BRDF model for the FY_3D images obtained from different observation angles was analyzed.The relative deviation between the apparent reflectance of each band of the sensor based on the BRDF model and that measured by the satellite was calculated.The results show that the difference between the corrected surface reflectance of different models is not more than 1%affected by the time and sun angle,and not more than 3%affected by the different combinations of the kernel functions of FY_3D.Furthermore,the average relative deviation of apparent reflectance from satellite observations calculated by the B1-B12 band model of MERSI-II in 2021 was less than 5.22%,whereas that from satellite observations calculated by the B1 and B2 band models in 2022 was more than 8%;the remaining bands were less than 5.74%.

关 键 词：辐射定标 BRDF模型 表观反射率 反射率基法 FY_3D MERSI-Ⅱ 

分 类 号：TP722.4[自动化与计算机技术—检测技术与自动化装置]